gonna struggle doin that on a pintara matt
even tho the r31 platform is different, the trans tunnel on the manual is narrower
*edit* - read that you're goin to do it with an auto, thats not so bad
if its pintara, you'll just need skyline crossmember and some RB30 engine mounts (as the RB20 / RB25 ones push it too far forward and fan chews out the back of the radiator)
if you can find a skyline to put it into, piece of cake. swap RB30 engine mounts off and onto the new motor, run loom, think theres like 5 wires to get it to basically power up (theres a wiki section on R31SC with this info from memory). If you score an S3, the auto is the same as 20DET and 25DET auto boxes (4sp electronic auto)